Telephone call timing circuit

ABSTRACT

A timing circuit which includes a pulse generator for generating a train of timed pulses for the duration of a data call on a telephone line. A first counting circuit repeatedly counts a predetermined number of pulses and generates an output pulse at the end of each group of pulses. A second counting circuit counts a predetermined number of output pulses from the first counting circuit and generates a further output pulse which operates a relay to energize an overtime register and disable the second counting circuit. The overtime register subsequently registers every time the first pulse of a group of pulses is counted.

Inventors Appl. No.

Filed Patented Assignee Derek Leyburn St. Laurent, Quebec;

James S. Kyles, Pointe Claire, Quebec, Canada Apr. 1 l, 1968 Apr. 6,1971 The Bell Telephone Co. of Canada Montreal, Quebec, Canada TELEPHONECALL TIMING CIRCUIT 6 Claims, 3 Drawing Figs.

U.S. Cl l79/7.1

....H04m1/l8 Field of Search 179/7. 1

References Cited UNITED STATES PATENTS OTHER REFERENCES General ElectricTransistor Manual, Seventh Edition (l964)pp131134 PrimaryExaminerl(athleen H. Claffy Assistant Examiner-J an S. BlackAtt0meyCurphey and Erickson ABSTRACT: A timing circuit which includes apulse generator for generating a train of timed pulses for the durationof a data call on a telephone line. A first counting circuit repeatedlycounts a predetermined number of pulses and generates an output pulse atthe end of each group of pulses. A second counting circuit counts apredetermined number of output pulses from the first counting circuitand generates a further output pulse which operates a relay to energizean overtime register and disable the second counting circuit. The

2,404,654 7/1946 Potts l79/7.1 overtime register subsequently registersevery time the first l 1/1949 Baker 179/7.1 pulse of a group of pulsesis counted.

CH PA-z Pia-2 P3-l E4 1):: CH g[ g ea X X i we PB-3 Pl-wx PULSE 5 XGENERATOR CH-l 1 X X {h- PA-3 Pl-3 P2 i i X l PM "-Pe-4 P2l PB-I X PA-lX X I: l P2-4 \\PB-5 P3 P2-2 PA PB P3-3 X i E P2-3 OT-l l PD-l l A xen-zPC PD TELEPHONE CALL TIMING CIRCUIT This invention relates to telephonecall timing circuit and more particularly to circuits for providingtiming and charging facilities for data type calls using regulartelephone lines.

The rate structure in use for automatic ticketing of toll calls includesa minimum basic charge for a predetermined time interval and an overtimecharge in which a selected increment of cost is added to the basiccharge for various overtime intervals. There has been a need for asimple, fast operating timing circuit particularly suited for individualapplications to data lines, and to measuring the duration of data calls,which may be as short as, for example, l seconds. Having that in mind,the timing circuit, in accordance with the invention includes a pulsegenerator for generating a train of timed pulses representative of thetime duration of a call in seconds. The timing circuit further includesa first counting circuit for repeatedly counting a predetermined numberof the pulses, each predetermined number of pulses forming a group ofpulses, and a second counting circuit responsive to the first countingcircuit for counting the above groups of pulses and for energizing anovertime register when a predetermined number of groups of pulses hasbeen counted. The overtime register subsequently registers every time agroup of pulses are counted.

The above circuit may be arranged to operate a call register when thefirst pulse is counted to register the call.

The invention will now be described with reference to the drawings whichrepresent a preferred embodiment of the invention and in which:

FIG. 1 illustrates a pulse counting circuit for counting a predeterminednumber of pulses generated by a pulse generator;

FIG. 2 illustrates a pulse counting circuit for counting a predeterminednumber of groups of pulses; and

FIG. 3 illustrates a register circuit.

When a toll call is answered, a ground is placed on lead CH from thetrunk circuit, as commonly known, to operate relay CH from potentialsource E1. The operation of relay CH closes contacts CH-l to connect thepulse generator PG to flip-flop circuit 10. The operation of relay CHalso closes contacts CI-I-2 and CH-3 for the pulse countings circuits ofFIGS. 1 and 2 respectively. In addition, the operation of relay CHcloses contacts CH-4 for initiating a circuit for the register circuitof FIG. 3.

On the first pulse generated by generator PG, relay PA is energizedthrough the circuit comprising potential source E2, resistor R2, relayPA, contacts PA-l, operated contacts CH-l, operated contacts PG-l andground. Contacts PG-l of pulse generator PG operate and release at arate of one interruption per second to generate a basic train of pulsesof one pulse per second. Relay PA locks operated through its owncontacts PA-l and contacts CH-S. Relay PB does not operate for theduration of the pulse as it is shunted by its own released contacts PB1.

When the ground pulse is removed, relay PB is operated through thecircuit comprising potential source E3, resistor R3, relay PB, operatedcontacts PAl, operated contacts CH-S and ground. Relays PA and PB remainoperated until the next ground pulse from pulse generator PG. Relays PAand PB of flip-flop circuit are then in a set condition.

The operation of relays PA and PB closes contacts PA2 and PB-2 of thepulse counting circuit of FIG. 1 and operates relay P1 through thecircuit comprising potential source E4, relay Pl, released contacts Pl-land P3-l, operated contacts PA2, PB-2, CH-2 and ground. Relay Pl locksoperated through its own contacts Pl-l and contacts PB-3 of relay PB orcontacts P31 of relay P3. The operation of relay P1 counts the firstpulse generated by pulse generator PG and in closing contacts P1-2 inFIG. 3 operates the call register relay C to register the beginning ofthe call. The registration of the call follows'the generation of thefirst pulse which is representative of the starting time of the call. Ifthe pulse generator operates at the frequency of one pulse persecond,the call registration is made within one second after initiation ofthem". The call register is not disclosed in detail since it is wellknown in the art.

On the next ground pulse from pulse generator PG, relay PA is shuntedthrough contacts PB-l of operated relay PB and is consequently released.Relay PB remains operated for the duration of the pulse. When ground isremoved from relay PB by the opening of contacts PG-l, relay PB isreleased. Relays PA and PB are, therefore, both released after thesecond pulse of pulse generator PG and the flip-flop circuit is said tobe in a reset" condition. The flip-flop circuit continues to operate orrelease (set or reset) on each alternate ground pulse from the pulsegenerator PG for the duration of the call.

When both relays PA and PB are released after the operation of relay P1,relay P2 of the pulse counting circuit is operated through the circuitcomprising potential source E4, relay P2, contacts P2-l, operatedcontacts Pl-3, released contacts PA3 and PB4, operated contacts CH2 andground. Relay P2 locks operated through its own contacts P2] andreleased contacts PB-S of relay PB or operated contacts P1-4 of relayP1. The operation of relay P2 counts the second pulse generated by thepulse generator PG. Relay P1 remains operated because contacts P3-l ofrelay P3 are still closed.

After the third pulse of pulse generator PG, relays PA and PB arereoperated and relay P3 of the pulse counting circuit is operated tocount the third pulse generated by the pulse generator through a circuitincluding potential source E4, relay P3, released contacts P32, operatedcontacts P2-2, operated contacts PA2, PB-2 and CH2 and ground. Relay P3locks operated through its own contacts P3-2 and operated contacts PB-5or P2-3 of relays PB and P2 respectively. Relay Pl remains operatedthrough operated contacts PB-3. Relay P2 remains operated throughcontacts P1-4.

After the fourth pulse from pulse generator PG, relays PA and PB arereleased. The release of relay PB opens contacts PB-3 and releases relayPl. Relay P2 remains operated through released contacts PB5. Relay P3remains operated through operated contacts P23 of relay P2.

After the fifth pulse from pulse generator PG, relays PA and PB areoperated. The operation of relay PB opens contacts PB-S and releasesrelay P2. Relay P3 remains operated through operated contacts PB-S.

After the sixth pulse from pulse generator PG, relays PA and PB arereleased. The release of relay PB opens contacts PB5 and releases relayP3.

The pulse counting relays operate in accordance with the followingtable:

Relay operated and the above sequence is repeated for the duration ofthe call to repeatedly count a predetermined number of the pulsesgenerated by the pulse generator PG.

Each time the combination of operated counting relays is PB and P3 only(when the sixth ground pulse is applied to flipflop circuit 10 torelease relay PA while relay PB is still energized), a ground pulse isapplied to relay PC of flip-flop circuit 11 th9ough the circuitcomprising potential source E5, resistor R5, relay PC, released contactsPC1, OT-l, operated contacts P3-3, released contacts P2 -4, operatedcontacts PB4, released contacts PA3, operated contacts CH-2 and ground.Relay PC locks operated through its own contacts PC-l and releasedcontacts OT-2. Relay PD is shunted by its own contacts PD-l and operatesonly after PB is released after the sixth pulse. The flip-flop circuit11 functions the same way as flip-flop l0 and is set and reset on eachalternate ground pulse from the pulse counting circuit of FIG. 1, thatis, after the sixth, the 12th, the 18th, the 24th and the 30th pulse.

When relays PC and PD operate after the sixth pulse, relay P4 in FIG. 2operates through the circuit comprising potential source E7, relay P4,released contacts P4-1 and PS-l,

operated contacts PC-Z and PD-Z, released contacts OT-3,

operated contacts CH-3 and ground. Relay P4 locks operated through itsown contacts P4-1 and released contacts P-2 or operated contacts PC-3.The operation of relay P4 opens contacts P4-2 in the call registercircuit FIG. 3 for preventing a false registration of the call register.

When relays PC and PD are released after the 12th pulse, relay P5 isenergized through the circuit comprising potential source E7, relay P5,released contacts P5-3, operated contacts P4-3, released contacts PC-4and PD3, released contacts OT-3, operated contacts CPI-3 and ground.Relay P5 locks operated through its own contacts. Relay P4 remainsoperated through released contacts PD-4.

When relays PC and PD are operated after the 18th pulse, relay P4remains operated through contacts PC-3. Relay P5 also remains operatedsince its holding circuit does not include any contacts of relays PC andPD.

When the 24th ground pulse is applied, relay PC is released openingcontacts PC-3. Since relay PD is not released until the 24th groundpulse is removed, relay P4 is not held operated by contacts PD-4 and isconsequently released. Relay P5 alone remains energized.

When relays PC and PD are operated after the 30th pulse, relay OT isenergized through the circuit comprising potential source E8, relay OT,released contacts OT-4, and P4-4, operated contacts PS-l, PC-Z and PD-2,released contacts OT-3, operated contacts CH3 and ground. Relay OT locksoperated for the remaining duration of the call through its own contactsOT-4 and operated contacts CPI-3. The operation of relay OT releasedrelays PC and PD at contacts OT1 and OT-2 to release the secondflip-flop 11 and to prevent further operation of the second countingcircuit. In addition, it releases relay P5 at contacts OT-3.

The operation of relay OT also closes contacts OT-5 in FIG. 3 to preparethe operate path of relay O of the overtime register. The overtimeregister is subsequently energized once every sixth pulse, for theremaining duration of the call, when contacts P1-2 of the pulse countingrelay P1 in FIG. 1 are closed. The overtime register is not disclosed indetail since it is well known in the art.

At the end of the call, ground is removed from the CH lead FIG. 1 whichreleases relay CH. The release of relay CH releases all operated relaysby opening contacts CH-l, CH-2, CH3, CH-4 and Cl-l-S.

We claim:

1. A timing circuit for measuring the duration of a call on a telephoneline comprising:

a. an overtime register;

b. pulse generating means responsive to the initiation of a call forgenerating timed pulses for at least the duration of said call;

c. first counting means for repeatedly counting a predetermined numberof said pulses, each of said predetermined number of pulses forming agroup of pulses, said counting means producing an output pulse each timea group of pulses has been counted;

d. second counting means responsive to the output pulses from said firstcounting means for producing an output pulse when a predetermined numberof said groups of pulses has been counted;

e. means responsive to the output pulse of said second counting meansfor conditioning the overtime register and for disabling said secondcounting means; and

f. means for enabling the conditioned overtime register thereafter inresponse to the first pulse of each succeeding group of pulses for theduration of the call.

2. A timing circuit as defined in claim I wherein said first countingmeans comprises a first flip-flop circuit responsive to said timedpulses, and first pulse counting relays responsive to said firstflip-flop circuit for counting said predetermined number of pulses andproducing said output pulses from said first counting rn ean s.

3. A timing circuit as defined in claim 2 wherein said second countingmeans comprises a second flip-flop circuit responsive to the outputpulses from said first counting means, and second pulse counting relaysresponsive to said second flipflop circuit for counting predeterminednumber of groups of pulses and producing said output pulse from saidsecond counting means.

4. A timing circuit as defined in claim 3 wherein said means responsiveto the output pulse of the second counting means is a relay.

5. A timing circuit as defined in claim 4 wherein said relay disablesthe second flip-flop circuit.

6. A timing circuit as defined in claim 5 wherein said means forenabling the conditioned overtime register comprises a predeterminedrelay of said first pulse counting relays.

1. A timing circuit for measuring the duration of a call on a telephoneline comprising: a. an overtime register; b. pulse generating meansresponsive to the initiation of a call for generating timed pulses forat least the duration of said call; c. first counting means forrepeatedly counting a predetermined number of said pulses, each of saidpredetermined number of pulses forming a group of pulses, said countingmeans producing an output pulse each time a group of pulses has beencounted; d. second counting means responsive to the output pulses fromsaid first counting means for producing an output pulse when apredetermined number of said groups of pulses has been counted; e. meansresponsive to the output pulse of said second counting means forconditioning the overtime register and for disabling said secondcounting means; and f. means for enabling the conditioned overtimeregister thereafter in response to the first pulse of each succeedinggroup of pulses for the duration of the call.
 2. A timing circuit asdefined in claim 1 wherein said first counting means comprises a firstflip-flop circuit responsive to said timed pulses, and first pulsecounting relays responsive to said first flip-flop circuit for countingsaid predetermined number of pulses and producing said output pulsesfrom said first counting means.
 3. A timing circuit as defined in claim2 wherein said second counting means comprises a second flip-flopcircuit responsive to the output pulses from said first counting means,and second pulse counting relays responsive to said second flip-flopcircuit for counting predetermined number of groups of pulses andproducing said output pulse from said second counting means.
 4. A timingcircuit as defined in claim 3 wherein said means responsive to theoutput pulse of the second counting means is a relay.
 5. A timingcircuit as defined in claim 4 wherein said relay disables the secondflip-flop circuit.
 6. A timing circuit as defined in claim 5 whereinsaid means for enabling the conditioned overtime register comprises apredetermined relay of said first pulse counting relays.